Lemurs at the San Francisco Zoo recently got some new playmates: pink plastic flamingos.

The lawn ornaments are part of an enrichment program that ensures animals are mentally stimulated.

While zoos try to keep animals in surroundings that closely mimic their wild environments, it's impossible for them to be as rich as the species' natural habitats.

That's why zoos provide social and environmental enrichment — in the form of toys, painting and even plastic flamingos — to many of the animals in their care.

"Sometimes this is a long-term, involved project, and sometimes it is as simple as providing a new, colorful and different-smelling object for a short period of time," said a San Francisco Zoo spokeswoman.

Introducing a new object like a lawn ornament gives animals like lemurs important mental stimulation, and observing their response to it can offer clues to the animals' mental health.

If an animal is apprehensive around a new object, it could indicate that it's experiencing an unnatural amount of stress.

However, if the animal is curious — like these lemurs are with their flamingos — it shows that the creature is comfortable in its environment and eager to explore.

Below, check out some adorable photos of the San Francisco Zoo's lemurs interacting with their flamingo lawn ornaments.

Lemur rule #1: Maintain eye contact at all costs.

This lemur takes a less direct approach.

See rule #1.

Curiosity is a sign of a good mental health for this ring-tailed lemur.